piaggio lc stops running @ w.o.t ?

[diesel27]

My nrg engine dies at full throttle after about 10 seconds . Gets to 80 kph easy then when I hold it open to go for max speed it just goes out. if I close the throttle and wait , power comes back ?

 

[TuningMatters]

Sounds like it's running too lean and dies due to overheating. Does go back on immediately after it dies, or do you have to wait a few minutes before it starts again?
Have you modified the air filter in any way? What tuning parts are installed? What's the size of your main jet?

Best,
Daniel

 

[diesel27]

Hi Daniel . Its originally was a purejet but I rebuilt it using the malossi carb conversion kit . Now runs a doppler endurance in tn9 bearings , stage6 sport pro mk2 , phbg 21mm black , stage6 glass reeds and intake and a yasuni R . Air filter malossi pod with 102 main

 

[TuningMatters]

21mm carb at 102 jet sounds ok, thos you could try going a bit bigger. Maybe try a 110 and see if performance is still there and if it continues to die!

 

[diesel27]

Thanks . I found 110 to be very rich . 105 was good to
3/4 throttle then less power at w.o.t and it still did this dying out problem . Just goes deep sound broop and nothing . I can coast with a closed throttle and it will come back with 1/4 throttle after 10 sec .102 jet cleaned it up to w.o.t but still this problem . Could the carb be too big ? Eg 19mm better ? Thanks Diesel

 

[TuningMatters]

Can you try attaching the stock airbox instead of the Malossi Filter? 21mm carb should be fine. 17.5 or 19mm would be good too and save some petrol but it should certainly run without issues on 21mm too!

 

[diesel27]

Ok I will try the stock airbox , the smallest main jet I have is 92 . Might be close ? The variator is set at 10k
With 6.1 gr rollers . Does that sound about right ?
Thanks for sharing your thoughts I really appreciate it

 

[TuningMatters]

Hi,
No problem. Maybe try the stock airbox with the current mainjet first and see what happens (should be very rich and probably turns off too). Try to listen if the symptoms are the same as with the Malossi Filter. Then go down to the smaller jet. 92 should be too lean. I suppose something around 95 should be good, tho it's ok if you go too lean for the testing, just to see how it behaves.
I suspect, that if the issue is not within jetting/filter, it might be the reedvalve / reeds. Variator should be fine. 6.1 sounds a bit heavy but if pullthrough out of the corners is good, it should be fine!

 

[Ben Dover Swe]

Hi,
No problem. Maybe try the stock airbox with the current mainjet first and see what happens (should be very rich and probably turns off too). Try to listen if the symptoms are the same as with the Malossi Filter. Then go down to the smaller jet. 92 should be too lean. I suppose something around 95 should be good, tho it's ok if you go too lean for the testing, just to see how it behaves.
I suspect, that if the issue is not within jetting/filter, it might be the reedvalve / reeds. Variator should be fine. 6.1 sounds a bit heavy but if pullthrough out of the corners is good, it should be fine!

Hey Diesel, did you fix this issue? Having the same. If you dont mind coming back and reporting that would help the community a lot

 

[diesel27]

Hi . Sorry about late update , i have been away.

I had a set of carbon reeds from stage6 to suit the stage6 reed cage im using . So out with the fiberglass , in with carbon .
With no other changes i went and tested it and it ran perfectly . Very strong acceleration to indicated 100kph and held pinned
to a best of, so far , indicated 117 kph .
Next i will try lighter rollers and maybe in future an R1200 exhaust ?

Hope this helps you Ben and thanks Tuning Matters ...

 

[Ben Dover Swe]

Hi . Sorry about late update , i have been away.

I had a set of carbon reeds from stage6 to suit the stage6 reed cage im using . So out with the fiberglass , in with carbon .
With no other changes i went and tested it and it ran perfectly . Very strong acceleration to indicated 100kph and held pinned
to a best of, so far , indicated 117 kph .
Next i will try lighter rollers and maybe in future an R1200 exhaust ?

Hope this helps you Ben and thanks Tuning Matters ...

Very helpful indeed, thanks for update! What made thexreeds the culprit, could they not open/close enough to feed the engine because they were too stiff, or whats up?
Seems like you have a powerful setup there, is it for daily use ur race? I am looking at a similar setup but worried about service intervals - no clue how often to change piston rings and other maintenence? You just inspect them now and then?

 

[rustybentwrench]

Could you be sucking the float bowl dry? Low vacuum at WOT may not open the safety valve.

just throwin that out there. for your consideration.